Don't know much about the mysterious Sleepy Night apart from that they have been putting out records since 2007 and what they put about themselves on their website.
Their output is mostly jazz and now the seriously interesting bootleg The Lost Quintet taken from a 9 November 1969 Rotterdam airshot featuring Miles with Wayne Shorter, Chick Corea, Dave Holland and Jack DeJohnette of which no studio recording exists hence the 'lost' nickname.
All five however are all on Bitches Brew within the bigger picture, a life, jazz-changing classic very much on all sensible jazz fans' minds this year given that come summertime the fiftieth anniversary of its release is reached cue hopefully a flood of media coverage but don't hold your breath.
Sound quality of the boot is really good, artwork, while a Mati Klarwein hommage, another matter entirely because it is completely pony as you can see. You can't always get what you want, eh, something sung not long after. Available on download, CD and vinyl.